Process of treating glauconite and similar materials.



. same are onto Fannnmcn rscnmnnn, or imwanx, new JERSEY, ASSIGNOR r0 RICHARD e. waennn, or new YORK, N. Y.

PROCESS OF TREATING GLAUCONITE AND SIMILAR MATERIALS.

Specification of Letters Patent.

Patented J an. 28, 1919.

Ne Drawing. Application filed April 13, 1917, Serial No. 161,851. Renewed December 12, 1918. Serial in the art to which it appertains to make and use the same.

The present invention comprises a process of converting'the potassium of glauconite, commonly called grcensand and similar materialinto a water-soluble condition, by treatnient hereinafter described.

In accordance with the process of my present invention, I heat the greensand, with a material which upon 'calcination leaves lime or its equivalent, which may be a material known as lime sand, and with a chlorid such as sodium chlorid. to convert the potassium present into the ehlorid, after which the material is leached to dissolve the chlo'rids of sodium arid potassium, which materials are thereafter separated by any suitable method. In place of sodium. chlorid, chlorid of the alkaline earth metals could be employed, as in my Patent No. 1,254,451.

Greensand marl is well known to consist inlpart of glauconite, a hydrous potassium iron silicate, in which the potassium exists in a state in which it is substantially insoluble water. The iron is partly as ferric compounds, and partly as ferrous compounds. With the above materials are also associated varying amounts of other (and for the purposes of the present invention, non-essential) constituents, which need not here be considered. The potash content varies considerably butl may be assumed to be, roughly from a to 7 perhaps averaging around 6% for the grades or ualities readily available in almost unlimited quantities. Other similar silicate materials containing iron and potassium may be employed in place'of the greensand, if so desired.

As a convertin. agent, foruse in the process I preferab y employ sodium chlogave the following analysis,

(32100;, 71.12% Mg'CO 3.81%

Fc. .O and A1 0 6.72% 310, 14.38% IKZO .4870

showing it to be essentially an impure form of calcium carbonate. Instead of this matcrial'other forms of calcium carbonate can be employed. 0. g. chalk, marble and cspecially ordinary marl, or sludges consistin essentially of CaCO from various manufacturing processes.

The limo sand and marl recommend themselves on account of the fact that these are found in large deposits located near to the greensand beds, and moreover both these materials are readily crushed or ground without excessive use of power, and can in many cases be mined cheaply by thc'use of steam shovels without the necessity of drilling,.blasting, etc.

The lime sand is particularly suitablefor the purpose for the reason that I have discovered that it contains some potassium 90. compounds which are rendered soluble in the process. For this reason I prefer to use this material, when available. The lime sand or equivalent material, when the mixture is subjected toheat, is first decomposed, the calcium carbonate therein being first broken up to produce CaO+CO. Obviously lime itself could be used, or any material containing considerable amounts of. CaCO or other alkaline earth metal carbonates.

The procedure for the conversion of the potassium into a water-soluble state, may be conducted as follows:

The greensand, lime sand, and salt are about mixed preferably in the proportions of 'Greensand 2000 lbs. Limesand 1000 to 1600 lbs. Sodium chlorid 700 lbs.

The mixture is. then ground, preferably so that 95% will pass through a screen'hav ng 100 meshes per linear inch, (which steps arepreferably performed without first drying the two minerals, which are usually obtained from the bedsin a somewhat damp thus producing a considerably lower yield of soluble potassium salt.

During its passage through the rotary kiln, substantially the entire amount of the ferrous compounds presentin the raw ma terial will be converted into ferric compounds. It is found, however, that although the material, inpassing through the rotary kiln, may have been heated for an hour or so, and although it may have been at or near the stated temperature of 800 to 820 C. for

say ten minutes, the reaction will generally not be complete at this time, since a considerable percentage of the potassium content of the mass is still in an insoluble state. It is accordingly desirable to maintain the mass at or about the same temperature for a'sufii' cient time to allow the completion of the reaction of the salt and iron potassium silicate. The iron now being completely oxidized it is not necessary to continue the oxidizing atmosphere. It is preferable to carry out this continuation of the heating operation, in a muflle. ratherthan in a rotary kiln, to thereby prevent volatilization, and consequent loss of potassium compounds, it being well known that there is less volatilization in a mufile than incontactwith a flame or with a strong currentof gases, at the same temperature. .To securethe conditions necessary for the further progress or completion of the reaction, the hot mixture will then be dropped into a soaking pit inwhich it is kept at or near the temperature of'800 to 820 C. for an hour more or less, toenable the completion-of the reaction initiated in the rotary kiln. The material, which may have bailed up more or less durin the heating, is leached with water, pre erably by systematically leaching with water while hot, the liquors clarified or filtered if neces- Laeaeae sary, concentrated, and the K01 and NaCl 66 separately crystallized out, theKCl purified if desired, and the NaCl returned to the first it is preferable that the ing, and. it is preferable that the gases con tain suilicienh free'oxygen .to be oxidizingin character, while in contact with the mixture being furnaced. This is for the reason that it is desired that the ferrous iron be con- 1 verted completely into the ferric state, dur- 7 ing the roasting process.

According to my investigationathe essential'reactions which take place in'the process as above described, are follows First the heat dries the material and then substantially, as

dehydrates the glauconite. This latter is 8 5 completed at a temperature of approximately 600 C. The dehydration tends to open up the glauconite and puts the same into a con- T dition in which it is readily amenable to the subse uent chemical reactions. At this same time t e ferrous compounds become oxidized to the ferric state. Beginning at the temperature of about 600 O.the CaCO begins to give ofi.'its G0,, with the formation of caustic lime. Beginning at about 700 C.,

an interchange takes place, between the NaCl and the potassium iron silicate to produce sodium iron silicate and potassium chlorid. For practical purposes I have found that it is desirable to carry the temperatur'e to about 800 to 820 0., and to maintain it at such temperature, until the reaction is completed. Some iron chlorid may be formed and this at once reacts with freelime to produce iron oxid and to form calcium chlorid.

In addition to these essential reactions,

probably some lime unites with free silica present to produce silicates. Perhaps also some lime reacts with potassium iron silicate to produce calcium iron silicate, calcium ,ferrite, etc., liberating soluble potassium compounds.

I regard the reaction of the'sodi-um chlorid on the potassium iron silicate as the most important as producing the major part of the conversion into soluble potassium salts. i

Without limiting myself to specific apparatus, I desire to state that the process may be carried out in the apparatus of my 00- pending ap lication filed of even date here I with, Seria No. 162,852.

I claim:

1 The herein that the hot gases only 70 p describedlprocess for the lfio treatment of materials containing hydrous f prises heating such silicate with a chlorid of an alkali-forming metal, in an oxidizing atmosphere, while in thepresence of an alkali, at a temperature above 700 (1., but below that necessary to produce any substantial clinkering of the mass; and thereafter maintaining the mass at an elevated temperature While under conditions incapable of inducing volatilization of the potassium chlorid, for a considerable period of time for the completion of the reaction.

2. In the treatment of materials containing hydrous iron potassium silicate for the production of soluble potassium compounds, the improvement which comprises heating such silicate with sodium chlorid, in an oxidizing atmosphere, while in the presence of an alkali, to a temperature above 700- (3., but below that necessary to produce clinkering of the mass.

3. The process of treating materials containing hydrous iron potassium silicate for the production of soluble potassium compounds, which comprises heating such a silicate with a chlorid of an alkali-forming -metal,'in an oxidizing atmosphere While in the presence of lime, at a temperature above 7 (1., but below that necessary to produce clinkering of the mass; and thereafter maintaining the mass at an elevated temperature while out of direct contact with the flames and the rapid currents of gases produced thereby, to prevent excessive vaporization of potassium chlorid.

4. In the treatment of materials containing hydrous iron potassium silicate for the production of soluble potassium compounds, the improvement which comprises reacting upon such silicate with a chlorid of an alkali-forming metal, while in the presence of a material which upon calcination leaves an alkaline earth metal oxid, to a tempera ture above 7 00 C., but below that necessary to produce clinkering of the mass; and after practically-all of the iron'has been oxidized, maintaining the temperature-for a considerable time, to cause completion of the reaction.

5. The process which comprises roasting at .a temperature above 700 C., but below that necessary to produce fusion, an inti mate mixture containing glauconite, sodium chlorid and calcareous material, all in a finely divided state, to initiate a reaction for the conversion of the potassium into a soluble state; thereafter maintaining the mass for a protracted period, at a temperature suitable for the continuance of such reaction, and at the same time preventing excessive volatilization of potassium chlorid,

and thereafter leaching the soluble material from the mass.

6. The process which comprises roasting at a temperature of about 800 to 820 C., an intimate mixture comprising -l'auconitc, sodium chlorid and a calcareous material, all in a finely divided state, to initiate a reaction for the conversion of the potassium intoa soluble state; thereafter maintalning the mass at a temperature approximately within the range of 800 to 820 0., for a protracted period for the contmuance of such reaction, and at the same time preventing excessive volatilization of potassium chlorid, and thereafter leaching the soluble material from the mass.

7. The process which comprises roasting at a temperature above 700 C., but below that necessary to produce fusion of the mass, an intimate mixture comprising greensand marl, sodiiun chlorid and lime sand, all in a finely divided state, to initiate a reaction for the conversion of the potassium into a soluble state; maintaining the mass for a protracted period at the temperature stated, for the continuance of the reaction, and at the same time preventing excessive vo1a-' tilization of potassium chlorid, and ,thereafter leaching the soluble material from the mass.

In testimony whereof I aflix my si iature.

. FREDERICK TSCHIR ER. 

